/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.loader;

import org.apache.catalina.LifecycleException;

public class WebappClassLoader extends WebappClassLoaderBase {

	public WebappClassLoader() {
		super();
	}

	public WebappClassLoader(ClassLoader parent) {
		super(parent);
	}

	/**
	 * Returns a copy of this class loader without any class file
	 * transformers. This is a tool often used by Java Persistence API
	 * providers to inspect entity classes in the absence of any
	 * instrumentation, something that can't be guaranteed within the
	 * context of a {@link java.lang.instrument.ClassFileTransformer}'s
	 * {@link java.lang.instrument.ClassFileTransformer#transform(ClassLoader,
	 * String, Class, java.security.ProtectionDomain, byte[]) transform} method.
	 * <p>
	 * The returned class loader's resource cache will have been cleared
	 * so that classes already instrumented will not be retained or
	 * returned.
	 *
	 * @return the transformer-free copy of this class loader.
	 */
	@Override
	public WebappClassLoader copyWithoutTransformers() {

		WebappClassLoader result = new WebappClassLoader(getParent());

		super.copyStateWithoutTransformers(result);

		try {
			result.start();
		} catch (LifecycleException e) {
			throw new IllegalStateException(e);
		}

		return result;
	}
}
